Roof jack structure

ABSTRACT

Presented is an improved roof jack structure that insures correct installation in relation to the aperture in the roof through which a flue or a vent tube associated with the roof jack structure must pass; and incorporating means for facilitating field inspection of the installed roof jack and vent pipe assembly to insure that the assembly adheres to building code regulations.

United States Patent m1.

Acosta 1 1 June 3, 1975 1 RooF JACK s'rRL'cTURi:

lm'cntor: Salvador .1. Acosta. 4895 'l'onino Dr. San Jose. Calif. 95123 [22] Filed: Dec. 18. 1972 :1 Appl. No; 316.133

1521 U5. Cl 98/60: 98/84 [51] Int. Cl. F231 17/02 158] Field of Search. 98/60. 81. 83. 8-1. 46. 98/42. (10: 126/307 [56] References Cited UNlTED STATES PATENTS 2.985.091 5/1961 Hatchcr i. 98/46 33 8.671 8/1965 Acosta 98/60 FORElGN PATENTS OR APPLlCATlONS 448.733 5 1948 Canada 98/81 Germany 98/66 R United Kingdom 98/66 R Primal Ii.\'umineI'-Meyer Perlin Assislunl li.\'uminm'Larry l. Schwartz filo/nay. Agent. or Firm-John J. Leavitt [57] ABSTRACT Presented is an improved roof jack structure that insures correct installation in relation to the aperture in the roof through which a flue or a vent tube associated with the roof jack structure must pass; and incorporating means for facilitating field inspection of the installed roof jack and vent pipe assembly to insure that the assembly adheres to building code regulations.

4 Claims, 5 Drawing Figures ROOF JACK STRUCTURE BACKGROUND OF THE INVENTION The invention relates to roof jack structures, particularly to roof jack structures adapted for installation on the roofs of commercial and residential buildings in association with a flue or vent pipe which connects an appliance within the building with the atmosphere outside the building. Such vent pipes conventionally extend through an enlarged aperture in the roof and terminate in a roof jack structure mounted over the roof aperture and designed to prevent debris from blowing into the open upper or discharge end of the vent pipe. More particularly, the improved roof jack structure forming the subject matter of this invention comprises an improvement over the roof jack structure disclosed and claimed in U.S. Pat. No. 3,398,671 issued in the name of the inventor herein.

The proper installation of a vent or flue pipe on an appliance such as a water heater or furnace usually includes a piece of large diameter sheet metal tubing extending from the appliance and connected to a doublewalled connector or B vent tube extending through an aperture in the roof. Most building codes require that the B vent tube be spaced a minimum lateral distance from any combustible material where the B vent tube passes through the roof and that the B vent project above the roof a prescribed distance. One of the difficulties encountered by installer of appliances is that not sufficient consideration is given to proper placement of the aperture in the roof in relation to the positional restrictions imposed for installation of the appliance. Stated another way, there is frequently a lack of communication and cooperation between the various trades involved with framing, roofing, and sheet metal contractors. It sometimes happens therefore that the person installing the appliance must improvise to provide a vent at all, giving rise to a tendency on the part of the installer to disregard the fact that the B vent tube should pass through the roof properly and be spaced a certain minimum distance from combustible roof material. This problem is most frequently caused by misplacing the aperture in the roof, or misplacing the roof jack in relation to the aperture, or both. Additionally, it has been found that sometimes the installation of the B vent tube does not meet the building codes for the area, which generally specify that the vent tube must terminate no less than a minimum specified distance above the roof. Where the vent tube constitutes a flue leading from the combustion chamber of a furnace or water heater, the flue becomes very hot and creates a fire hazard if placed in contact with combustible roof material. Accordingly, one of the objects of the present invention is to provide an improved roof jack structure which includes downwardly depending flange means on the flashing portion of the roof jack structure so that the roof jack may be accurately positioned in the roof aperture, and so that the downwardly depending flange means functions as a cold non-combustible separator disposed between the associated flue or vent tube and adjacent combustible material.

It is well known that heat may be conducted very efficiently between a hot body and a cold body. In a roof jack assembly including a B vent connector tube, the vent tube may be a hot body while the flashing, contiguous to combustible material may be considered as the cold body. Accordingly, another object of the invention is to provide a roof jack structure incorporating a flashing member associated with a conventional flue or B vent tube so that passage of heat from the flue or B vent tube is generally restricted, but which causes heat that is transferred to be spread uniformly over the broad expanse of the roof flashing member, thus lowering the heat content of the flashing well below dangerous limits.

Most building codes require that after installation of an appliance and placement of a flue or vent tube, that the installation be subjected to an inspection by proper authority. Inspectors check to see whether the vent or flue tube provides an unobstructed passage between the appliance and the atmosphere outside the building. To make such an inspection, the inspector must generally peer downwardly on the roof jack from above so as to visually observe that the vent tube terminates the proper distance above the roof line. However, to prevent gusts of wind and debris from blowing into the open end of the vent tube or flue, it is desirable to superimpose over the open end of the vent tube some type of covering which'will inhibit such gusts ofwind from blowing into the open end of the flue or vent tube, and which will prevent passage of debris into the upper open end of the vent tube.

The placement of such cap or covering increases the difficulty of a proper inspection and thus contributes to the temptation and tendency of some inspectors to inspect only one or two out of a multi-roof jack installation, thus contributing to the probability that an improper installation will not be discovered. In U.S. Pat. No. 3,398,671, an attempt was made to obviate this problem by providing an inverted generally U-shaped baffle over the open end of the flue or vent tube, attached permanently to the roof jack and having a projecting tab adapted to be threaded through a slit formed by a piece of metal struck from the supporting structure to normally retain the inverted U-shaped baffle locked in position. The inspector was expected to laboriously unbend the tab so that it could be withdrawn from its bracket, make his inspection and laboriously replace the tab and rebend it to lock the baffle in place. Such construction exposes the inspector to being cut by the sharp corners of the sheet metal structure, and requires considerable effort on the part of the inspector to unlock and subsequently lock the baffle after inspection. Accordingly, it is a still further object of the present invention to provide an improved roof jack structure incorporating inspection plate means that may be easily removed in its entirety without danger, and which may just as easily be replaced following inspection.

The discharge end of flue or vent tubes are frequently obstructed by the conventional roof jack structure withwhich they are associated by virtue of insertion of the flue or vent tube into the roof jack structure for a greater distance than is intended. When this occurs, the upper open end of the flue or vent tube approaches too closely the baffle adapted to prevent gusts of wind and debris from blowing into the upper open end of the flue or vent tube, and thus diminishes the effective crosssectional area of the discharge opening around the upper end of the flue or vent tube through which products of combustion must escape. Accordingly, another object of the present invention is the provision of stop means in an improved roof jack structure to insure that the flue or vent tube will be properly oriented with respect to the roof jack structure to prevent such obstruction or reduction of the effective cross-sectional area of the opening surrounding the upper open end of the flue or vent tube.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following desccription and the drawings, It is to be understood however that the invention is not limited to the embodiment illustrated and de scribed as the invention may be embodied in various forms within the scope of the appended claims.

BRIEF SUMMARY OF THE INVENTION In terms of broad inclusion, the improved roof jack structure of the invention comprises a roof flashing unit having a large rectilinear flashing portion adapted to lie flatly on the roof boards. The flat rectilinear flashing portion is provided with oppositely extending flanges, one of the flanges functioning to orient the flashing portion in relation to the aperture in the roof boards, and the other oppositely extending flange constituting a roof safe and being generally conical in its configuration and projecting upwardly from the roof. The upwardly projecting conical roof safe forms a pivotal bearing support for the lower end of a tubular generally conical roof safe extension member, the lower end of which is superimposed around and pivoted to the conical roof safe and is of somewhat larger diameter than the associated roof safe so that the upwardly extending roof safe extension may pivot in relation to the underlying roof safe for purposes of proper alignment of the roof safe and roof safe extension with a flue or vent tube extending therethrough.

The upper end of the roof safe extension is circumscribed by and supports a roof jack baffle assembly within which the upper end of the tapered or conical roof safe extension terminates. Means are provided within the baffle assembly and associated with the upper open end of the conical roof safe extension to limit the degree of insertion of a flue or vent tube thereinto. Means are also provided removably associated with the baffle assembly and the upper open end of the conical roof safe extension constituting a cap or baffle plate to prevent gusts of wind and debris from blowing into the open end of the flue or vent tube.

A DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the improved roof jack structure, the roof boards and vent tube being shown in broken lines.

FIG. 2 is a plan view taken in the direction indicated by the arrows on line 22 in FIG. 1. A portion of the roof flashing has been broken away to reduce the size.

FIG. 3 is an enlarged fragmentary elevational view partly in vertical section, illustrating the insertion limit means for the vent tube and the detachable baffle cap associated with the baffle assembly.

FIG. 4 is a fragmentary sectional view in enlarged scale illustrating the lug arrangement for retaining and releasing the baffle cap from its position over the open end of a vent tube to permit ready detachability of the baffle cap for purposes of inspection.

FIG. 5 is a fragmentary bottom plan view taken in the direction of the arrow 5 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In terms of greater detail, the improved roof jack structure of the invention is illustrated in FIG. 1 in position of installation in conjunction with roof boards 2 having an aperture 3 therein through which a flue or vent tube 4 is adapted to extend upwardly from an appliance (not shown) positioned within a building. The improved roof jack structure in its entirety is designated generally by the numeral 6, and includes a roof flashing unit designated generally by the numeral 7, a roof safe extension sleeve designated generally by the numeral 8, and a baffle assembly designated generally by the numeral 9.

Referring to FIG. 1, the roof flashing unit 7 includes a rectilinear, apertured, flat base or flashing plate 12 adapted to be secured permanently to the roof structure, the aperture in the flashing plate being in generally aligned association with the aperture 3 in the roof structure. The underside 13 of the flat flash plate 12 is provided with a depending flange 14 having an oval or tubular configuration, the major axis of the oval flange extending from left to right as viewed in FIG. 1 so that when the roof jack is installed as illustrated in FIG. 1, the flange 14 projects through roof aperture 3 formed in the roof boards. It will thus be seen that when proper dimensions and tolerances are observed in cutting the aperture 3, which may or may not be ovate, the roof jack cannot be improperly installed. The tubular oval flange 14 is secured to the underside of the flash plate 12 by means of an integral circumferential flange 15 spot welded or otherwise secured to the underside 13 of the flash plate.

Referring to FIG. 5, it will there be seen that the tubular oval flange 14 is fastened to the underside 13 of the flash plate in association with circular aperture 16 formed in the plate. The diameter of the circular aperture conveniently coincides with the minor diameter of the tubular oval flange, the tubular oval flange being offset along the major axis of the oval flange from the center 17 of the circular aperture 16.

On the opposite or top side of the flash plate 12 and secured thereto adjacent the periphery of the aperture 16, is an upwardly extending roof safe 18 having a conical configuration as illustrated best in FIG. 1, the roof safe being of conventional design and having an upper open end or edge 19 of appropriate inside diameter to snugly receive therewithin and give lateral support to the connector tube or flue 4 as will hereinafter be explained. At its lower end, the roof safe is provided with a circumferential flange 21 attached to the flash plate 12 adjacent the aperture 16 in a well known conventional manner to provide water-tightness at this union. In the present instance, the roof safe is designed for use with roof jacks of the type disclosed and claimed herein which adjust from O pitch to 5-12 pitch of a roof on which the roof jack is installed.

Pivotally mounted on the walls of the roof safe intermediate the upper and lower ends thereof is a roof safe extension sleeve 8, conveniently fabricated from galvanized sheet metal, and tapered to provide an upper end portion 22 having an internal diameter adapted to snugly receive and give lateral support to the outer diameter of the vent or flue tube 4 extending thereinto. The lower end 23 of the roof safe extension sleeve is of larger diameter to fit loosely over and around the upper end 19 and mid-section of the roof safe. The lower end edges 24 of the lower end portion of the roof safe extension sleeve are cut away as shown to provide a pair of diametrically opposed lugs 25 adapted to receive pivot pins 26 extending through the conical wall of the associated roof safe so as to provide a pivotal mounting and support for the roof safe extension sleeve on the roof safe. The cutaway lower edges 24 provide clearance between the lower portion of the roof safe extension sleeve and the roof safe to permit the extension sleeve to pivot to the left or to the right as viewed in FIG. 1, thus providing for angular adjustment of the extension sleeve with respect to the roof safe on which it is mounted to accommodate differently pitched roofs from a flat or pitch roof to a roof having a -12 pitch. Obviously, it would require a mere modivication of certain dimensions to accommodate roofs of greater pitch.

It will thus be seen from the construction illustrated in the drawings and described above that in the absence of the flue or vent tube 4, the roof safe extension sleeve is permitted to pivot within prescribed limits on the pivotal mounting pins 26. After the vent tube has been inserted through the roof safe, however, and especially after the upper end of the vent tube has been snugly received within the inside diameter of the upper end portion 22 of the roof safe extension sleeve, it will be apparent that there can be no relative movement between the roof safe extension sleeve and the supporting roof safe.

After installation of the roof jack structure, it is important that means be provided to limit the degree of extension into the roof jack structure of a vent tube or flue pipe 4. It is important also to prevent gusts of wind from blowing down the vent tube or flue pipe, and additionally to prevent the open end of the flue or vent tube from being cluttered with debris that might be blown thereinto by gusts of wind. To this end, the roof jack structure of the invention is provided with a baffle assembly 9 mounted on the upper end portion of the roof safe extension sleeve. The baffle assembly illustrated incorporates a short tubular section 31 having a top edge 32 and a lower edge 33. The short tubular section is mounted coaxially with respect to the open upper end of the associated roof safe extension sleeve by a plurality of strap members 34, each having a leg portion 36 appropriately spot welded or otherwise secured to the upper side portion 37 of the roof safe extension sleeve, the strap 34 continuing upward beyond the upper edge 22 of the extension sleeve to provide a spacer portion 38. At its upper end, the spacer portion 38 is integral with a horizontally extending spoke section 39 the outer end of which is provided with an upwardly extending flange 41 spot welded to the inner periphery 42 of the short tubular section 31. As seen in FIG. 2, there are conveniently three such strap members 34, the straps being proportioned to rigidly support the short tubular section 31 coaxially with respect to the open upper end of the roof safe extension sleeve and the vent tube or flue pipe 4 inserted therein.

The strap members 34 are at 120? intervals and func tion to support a flat baffle plate 43 having a handle 44 in a position spaced above the open end 22 of the roof safe extension sleeve. The distance that the baffle plate 43 is spaced above the open end of the extension sleeve is determined by the length of the spacer portion 38 of the strap members, this spacing being sufficient to provide an annular opening of substantially 360 adjacent the upper open end of the roof safe extension sleeve. The annular opening is of sufficient cross-sectional area to easily discharge all of the products of combustion that emanate from the vent tube or flue pipe 4. It is important to note that with the exception of the rather limited area occupied by the spacer portion 38 of strap members 34, the opening defined between the underside of the baffle plate 43 and the upper edge 22 of the extension sleeve permits discharge of such products of combustion through substantially 360 rather than in a limited manner and direction as with conventional roof jack structures.

To removably secure the baffle plate 43 in tight engagement with the baffle assembly, the spoke portion 39 of each strap member is provided with a raised lug 46 struck from the spoke section and raised above the remaining portion of the strap a sufficient amount to permit the peripheral edge portion 47 of the baffle plate to slip under the lug andbe retained thereby. As illustrated in FIGS. 2 and 4, the peripheral edge of the baffle plate is provided with a release aperture 48 formed by striking a lug 49 from the peripheral edge of the baffle plate, the aperture 48 permitting the edges of the baffle plate opposite aperture 48 to be slipped under two of the raised-lock lugs 46 when the aperture 48-is coincident with the third lock lug. Thereafter, rotation of the baffle plate by means of the handle 44 will shift the aperture 48 into the position illustrated in full lines in FIG. 2, so that all of the lock lugs 46 overlie a perpheral portion of the baffle plate, thus retaining it securely in position.

It will thus be seen that upon inspection, all that the inspector need do is to rotate the baffle plate so that the aperture 48 is coincident with one of the lock lugs 46 and then slip the baffle plate laterally and upwardly, exerting pressure on the handle 44 in the direction of the aperture 48, thus causing the opposite edges of the baffle plate to slip out from under the associated lock lugs 46. The reverse procedure is followed to replace the baffle plate after the inspection has been completed.

One of the factors that an inspector looks for upon inspection is to make sure that the vent or flue 4 extends upwardly into the roof jack structure a sufficient amount. To facilitate the performance of this function by the inspector, and to facilitate assembly of a vent or flue tube within the roof jack, the baffle assembly is provided with means for limiting upward insertion of the vent or flue tube within the roof safe extension sleeve. Referring to FIG. 3, it will there be seen that the spacer portion 38 of at least one of the strap members 34 is provided with a radially inwardly extending lug 51 struck from the strap and positioned so that the underside of the lug is coincident with the top edge 22 of the roof safe extension sleeve. Since the lug 51 projects radially inwardly from the strap member, it will be seen that the lug functions as a stop to limit upward movement of the enclosed flue or vent tube 4.

Thus, upon installation, all that the installer of an appliance within the building need do is to insert a connector or vent tube of appropriate diameter upwardly through the roof and roof jack until it abutts against the stop lug or lugs 51. He may then secure the vent or flue in any acceptable manner, the conventional practice being to utilize a sheet metal screw 52 adjacent the upper edge portion of the roof safe extension sleeve to prevent the flue or vent tube from slipping downwardly out of its proper position. In the alternative, the connector or vent may be cut to appropriate length so that when interposed between the lugs 51 and the appliance, the spacing is such as to retain the vent tube in proper position.

It will of course be understood that while the enbodiment chosen for illustration utilizes a generally cylindrical baffle assembly, any other shape, including an oval baffle assembly, may be utilized without departing from the spirit of the invention.

Obviously, roof jack structures of different dimensions may be fabricated correlated to the standard sizes of flue or vent tubes that are manufactured. It will also be apparent that while only one means for limiting the extension of the vent or flue into the roof jack structure has been shown, several other means will be apparent to those skilled in the art.

Having thus described the invention, what is claimed to be novel and sought to be protected by letters patent is as follows:

1. A roof jack assembly adapted for installation on the roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising:

a. a roof flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof;

b. a tubular roof safe secured by one end to one surface of said flash plate in association with said aperture therein and providing an open end remote from said flash plate;

c. a roof safe extension sleeve having one end thereof pivotally mounted on said roof safe so that said open end of the roof safe projects inwardly into said roof safe extension sleeve;

d. a baffle assembly mounted on the end of said roof safe extension sleeve remote from said roof safe, said baffle assemmbly including a tubular baffle member circumscribing the upper end of said roof safe extension sleeve and supported thereby, and a flat baffle plate rotatably supported for detachability in spaced relationship to the open upper end of said roof safe extension sleeve; and

e. strap means disposed between the upper end portion of said roof safe extension sleeve and said tubular baffle member circumscribed thereabout and including a lock lug, said flat baffle plate including an aperture and being detachably secured to said strap means in a manner to permit rotation of the flat baffle plate to effect alignment of the lock lug and aperture and effect detachment thereof from the strap means for purposes of inspection after the roof jack assembly has been installed; and

f. means for limiting penetration of said roof safe extension sleeve by said flue vent.

2. The combination according to claim 1, in which said flat flash plate is provided with a flange unit mounted on the opposite side of said flat flash plate from said roof safe and adapted to extend through the aperture therein without contacting said flue vent or the products of combustion emanating therefrom.

3. A roof jack assembly adapted for installation on the roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising:

a. a roof. flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof;

b. a tubular flange secured to the underside of said flat flash plate and adapted to project through the aperture in said roof when said roof jack is assembled thereon, said tubular flange being ovate in configuration and lying offset in the direction of its major axis from the aperture in said flash plate;

c. tubular roof safe secured by one end to the opposite side of said flat flash plate from said tubular flange;

d. a roof safe extension sleeve pivotally mounted at one end on said roof safe and extending upwardly away from said flash plate to an open upper end; and

e. a baffle assembly mounted on the upper end of said roof safe extension sleeve and including means circumscribing the open upper end thereof to prevent gusts of wind from blowing directly across the open end of the roof safe extension sleeve, and means within said circumscribing means to prevent debris from being blown into the open upper end of said roof safe extension sleeve and defining with the upper end of said extension sleeve an annular passageway extending substantially 360 thereabout.

4. A roof jack assembly adapted for installation on a roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising:

a. a roof flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof;

b. a tubular roof safe secured by one end to one surface of said flash plate in association with said aperture therein and providing an open end remote from said flash plate;

c. a roof safe extension sleeve having one end thereof pivotally mounted on said roof safe so that said open end of the roof safe projects inwardly into said roof safe extension sleeve;

d. a baffle assembly mounted on the end of said roof safe extension sleeve remote from said roof safe, said baffle assembly including a tubular baffle member circumscribing the upper end of said roof safe extension sleeve and supported thereby, and a flat baffle plate rotatably supported for detachability in spaced relationship to the open upper end of I said roof safe extension sleeve;

e. said baffle assembly including a plurality of strap members secured to the upper end of said roof safe extension sleeve at degree intervals, each of said strap members including a leg portion secured to said roof safe extension sleeve adjacent its upper end, a spacer portion projecting above the associated open end of said roof safe extension sleeve and radially extending spoke sections the free ends of which are secured to the circumscribing tubular baffle member, said flat circular baffle plate having a release aperture formed in its periphery, said baffle plate being adapted to detachably overlie said radially extending spoke sections, and lock lugs formed on said strap members and cooperable with said release aperture when said release aperture is in registry with one of said lock lugs to permit the periphery of said baffle plate to slip under said lock lugs whereby rotation of said baffle plate displaces the release aperture out of registry with the lug to place the periphery of the baffle plate into detachable engagement under said lugs operable to lock the flat baffle plate in spaced position above the open end of said roof safe extension sleeve. 

1. A roof jack assembly adapted for installation on the roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising: a. a roof flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof; b. a tubular roof safe secured by one end to one surface of said flash plate in association with said aperture therein and providing an open end remote from said flash plate; c. a roof safe extension sleeve having one end thereof pivotally mounted on said roof safe so that said open end of the roof safe projects inwardly into said roof safe extension sleeve; d. a baffle assembly mounted on the end of said roof safe extension sleeve remote from said roof safe, said baffle assemmbly including a tubular baffle member circumscribing the upper end of said roof safe extension sleeve and supported thereby, and a flat baffle plate rotatably supported for detachability in spaced relationship to the open upper end of said roof safe extension sleeve; and e. strap means disposed between the upper end portion of said roof safe extension sleeve and said tubulAr baffle member circumscribed thereabout and including a lock lug, said flat baffle plate including an aperture and being detachably secured to said strap means in a manner to permit rotation of the flat baffle plate to effect alignment of the lock lug and aperture and effect detachment thereof from the strap means for purposes of inspection after the roof jack assembly has been installed; and f. means for limiting penetration of said roof safe extension sleeve by said flue vent.
 1. A roof jack assembly adapted for installation on the roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising: a. a roof flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof; b. a tubular roof safe secured by one end to one surface of said flash plate in association with said aperture therein and providing an open end remote from said flash plate; c. a roof safe extension sleeve having one end thereof pivotally mounted on said roof safe so that said open end of the roof safe projects inwardly into said roof safe extension sleeve; d. a baffle assembly mounted on the end of said roof safe extension sleeve remote from said roof safe, said baffle assemmbly including a tubular baffle member circumscribing the upper end of said roof safe extension sleeve and supported thereby, and a flat baffle plate rotatably supported for detachability in spaced relationship to the open upper end of said roof safe extension sleeve; and e. strap means disposed between the upper end portion of said roof safe extension sleeve and said tubulAr baffle member circumscribed thereabout and including a lock lug, said flat baffle plate including an aperture and being detachably secured to said strap means in a manner to permit rotation of the flat baffle plate to effect alignment of the lock lug and aperture and effect detachment thereof from the strap means for purposes of inspection after the roof jack assembly has been installed; and f. means for limiting penetration of said roof safe extension sleeve by said flue vent.
 2. The combination according to claim 1, in which said flat flash plate is provided with a flange unit mounted on the opposite side of said flat flash plate from said roof safe and adapted to extend through the aperture therein without contacting said flue vent or the products of combustion emanating therefrom.
 3. A roof jack assembly adapted for installation on the roof of a building in association with a flue vent connector tube projecting above the roof through an aperture therein, comprising: a. a roof flashing unit comprising a flat flash plate having an aperture therein and adapted to be superimposed over the aperture in the roof; b. a tubular flange secured to the underside of said flat flash plate and adapted to project through the aperture in said roof when said roof jack is assembled thereon, said tubular flange being ovate in configuration and lying offset in the direction of its major axis from the aperture in said flash plate; c. tubular roof safe secured by one end to the opposite side of said flat flash plate from said tubular flange; d. a roof safe extension sleeve pivotally mounted at one end on said roof safe and extending upwardly away from said flash plate to an open upper end; and e. a baffle assembly mounted on the upper end of said roof safe extension sleeve and including means circumscribing the open upper end thereof to prevent gusts of wind from blowing directly across the open end of the roof safe extension sleeve, and means within said circumscribing means to prevent debris from being blown into the open upper end of said roof safe extension sleeve and defining with the upper end of said extension sleeve an annular passageway extending substantially 360* thereabout. 